Sansui 9090 Restoration

Raccoon1400

Super Member
Got my hands on a sansui 9090 to restore.
Needs:
-new outputs. Someone rebuild one channel with outputs rated for half the power of the originals. (I can use MJ21194?)
-AM antenna missing
-needs new jumpers, will make them out of brass rod
-relamp (will get bulbs from dgwojo)

I am planning on doing a full recap/restore.

What filter caps should I use?

Anyone have suggestions?
 
-new outputs. Someone rebuild one channel with outputs rated for half the power of the originals. (I can use MJ21194?)

What have they put in there? Curious minds are active here.....

The suggestions made by avionic are of course exactly right.....
 
What have they put in there? Curious minds are active here.....

The suggestions made by avionic are of course exactly right.....
toshiba 2SD371. Rated 50W instead of 100W.


I could use the panasonic filter caps, but does anyone know if there are better ones I could use?
 
If the power switch still works, parallel both sets of terminals to double the current capacity.

There is a flaw in the 9090, where if the protection relay opens the amp's output is shorted to ground. Search on dr8audio posts to find it.

I'm doing another one now, too.
 
Looking at the driver board, someone has been messing with it. Some components are on the back. Not sure what is supposed to be how it is, or what has been hacked. Also note the resistor going from R43 to R55. Is it supposed to be there, or should R43 and 55 be there instead?
One of the bias devices has been replaced, I would like to replace both. What part is best?
Also I see a couple gumdrop diodes to replace.
Are there any fusistors?
 

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This is typical Sansui factory 'Oops!' work. If you work on Sansui gear for any length of time, you get used to seeing it.

Lots of signs of hacking in this unit, including
-outputs replaced with ones rated for half the power
-a couple broken traces on the driver board
-one of the fuses was replaced on driver board
-a couple caps replaced on input selector board


How much of that do you figure was from the factory? They wouldn't have blown it up at the factory, or would they?
 
Looking at the driver board, someone has been messing with it. Some components are on the back. Not sure what is supposed to be how it is, or what has been hacked. Also note the resistor going from R43 to R55. Is it supposed to be there, or should R43 and 55 be there instead?
One of the bias devices has been replaced, I would like to replace both. What part is best?
Also I see a couple gumdrop diodes to replace.
Are there any fusistors?

look original...from Sansui factory

except for the fuse on the back...
might be original too.
 
Recapped most of the tuner board, now I can't get the tuner to do anything, am or fm. No meter movement or sound. Checked for bridged solder, backwards caps, didn't see anything. I lifted the front end as shown in the thread dr*audio linked. Thought maybe a wire came loose but can't find one. Any suggestions?
 
Check the power supply for the tuner. It's that little board on the left front. The resistor and transistor like to desolder themselves.
 
Measure the voltage...

The 8V supply is working, but I am getting <1V on the 35V supply. When I disconnect the board, the supply reads as it should. As far as I can tell nothing is shorted on the board, or bridged.

Haven't recapped this board yet.
And it was working great before I recapped the tuner board.

I suppose the next thing would be to disconnect the regulator board from the tuner board and measure the voltage again? I will try that when I get home.
 
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